SYNTHESIS OF HYDROXYAPATITE POWDER FROM EGG SHELL AND ITS COATING BY PLD PROCESS ON SS 316L VARYING LASER ENERGY

Abstract

Hydroxyapatite (HA) is a attractive biomaterial mainly used in bone and tooth implants because it closely resembles human tooth and bone mineral and has proven to be biologically compatible with these tissues. Nanocrystalline Hydroxyapatite (HA), which is similar in composition and crystal structure of natural bone, is found to ideal bone graft substitute due to its controlled resorption and its osteoconductive nature in the body. In this work stoichiometric hydroxyapatite is synthesized using hen's Eggshell (as calcium source) and ortho-phosphoric acid by wet precipitation method. Through this process eggshell can be used as a possible material recycling technology for future waste management and ecology. Also, eggshell originated HA is a potential ceramic, which could be useful as an inexpensive ceramic for biomedical applications. X-ray diffraction (XRD) technique is employed to investigate the formation of HA phase and conventional Energy-dispersive X-ray spectroscopy (EDAX) analysis is adopted to estimate the amount of calcium and phosphorous Thermo Gravimetric/Differential Thermal Analysis (TG—DTA) was carried out to investigate the thermal stability of HA powder. Fourier Transform Infrared (FTIR) spectroscopy show the characteristic peaks for phosphate and hydroxyl groups. Scanning electron microscopic (SEM) test is being done at different magnification to understand the morphology of HA powder. Inspite of the advantages of HA it has also certain limitation like inferior mechanical properties which does not make it suitable for long term load bearing application, hence various research is going on in development of hydroxyapatite coating over various metallic implants. These metallic implants posses good mechanical properties and HA coating take care of good bioactivity and bio conductivity. The aim of the present work is to deposit hydroxyapatite coating over SS 316L by pulse laser deposition (PLD) technique by varying laser energy. To know the effect of this variation, the coatings were then characterized in detailed by X-Ray diffraction, SEM, AFM and EDAX analysis.